When a musician plays a wind instrument, such as a clarinet (woodwind) or trumpet (brass), the musician blows air from his or her mouth across one or two reeds and through the instrument. In simplified terms, the air moving across the aareed causes the reed to vibrate and the frequency of the resulting sound is established by the musician covering and uncovering holes in the body of the instrument.
In order for the reed to vibrate in the correct manner, the musician's mouth and tongue must be in proper positions. However, as air is blown from the mouth into the instrument, the mouth tends to distort, causing an improper airflow. Distortion may be described as the corners of the mouth moving further from the mouthpiece. Two muscles that are involved are the orbicularis orbis, a muscle that encircles the mouth, and the buccinators, a muscle in the cheeks. Strengthening these muscles is important for proper mouth position (embouchure or ambature) and to reduce distortion. And, while wind musicians may attempt to practice proper mouth position, it may be very difficult to know when the two muscles are being used, and even more difficult to know when they are being used in the proper manner.